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Path: utzoo!utgpu!water!watnot!watmath!clyde!cbatt!ihnp4!kitty!larry
From: larry@kitty.UUCP
Newsgroups: comp.sys.att
Subject: Re: A/D board for 3b2/300?
Message-ID: <1617@kitty.UUCP>
Date: Thu, 26-Feb-87 20:10:23 EST
Article-I.D.: kitty.1617
Posted: Thu Feb 26 20:10:23 1987
Date-Received: Sat, 28-Feb-87 06:39:43 EST
References: <698@bgsuvax.UUCP>
Organization: Recognition Research Corp., Clarence, NY
Lines: 41
Summary: Data acquisition for 3B2

In article <698@bgsuvax.UUCP>, duncan@bgsuvax.UUCP (Comer Duncan) writes:
> 
> We have a couple of 3b2/300s and desire to use one for
> interfacing to experiments.  I am interested to know
> about any and all A/D boards which are known to WORK
> in a 3b2/300.  Our requirements are quite standard--
> 16 bits, not super speed but reasonable.
> 
> I would like to know the properties and costs of such
> boards as well any REAL experiences anyone has had
> with utilizing them in laboratory environments.

	My organization has done an extensive amount of analog signal
processing on 3B2's for scientific instrument and process control
applications in the past 2-1/2 years.  All of this signal processing
is in "quasi" real-time.
	We perform A/D, D/A and parallel I/O interfacing using external
devices which connect to the serial ports of the 3B2.  We use external
data acquisition systems such as the Burr-Brown PCI-3000, and interface
them to the 3B2 at 9600 baud.
	We also design our own microprocessor-based interface devices which
consist of an A/D converter with mux, microprocessor, buffer memory, and
serial port.  These interface circuits are comparatively simple and
inexpensive to design.
	Unfortunately, I know of no off-the-shelf analog signal acquisition
device which plugs directly into the 3B2 data bus.  I have toyed with the
design of such a device from time to time, but have elected not to go that
route for the time being.  One reason is that the available I/O board
area and outside-world connector-space is limited.  Another reason is the
effort involved to assure the Grand High Exaulted Mystic Rulers of AT&T
that our board design won't damage customer's 3B2's and void warrantys.
	While I would like to see someone place such a board on the
market as a product, I suspect that it is unlikely due to the comparatively
few 3B2's used for this type of application.  *I* think the 3B2 has some
good points for this type of application, but, well, the rest of the world
doesn't necessarily agree with me...

<>  Larry Lippman @ Recognition Research Corp., Clarence, New York
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